Telephone system



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T. F. CROCKER TELEPHONE SYSTEM Filed July 28, 1938 1l Sheets-Sheet 4INVENTOR. THOMAS F'. CROCKER ATTORNEYS.

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TELEPHONE SYSTEM Filed July 28, 193e May 14, 1940.

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T. F. CROCKER TELEPHONE SYSTEM Filed July 28. 1958 11 sheets-sheet 111170 To TOLL To 2.11.9 55m/10E To 352 To R s( D osERvmG R810 1.5.0.C1300 oPER'soPER'S. oPER's. oPER's Pos Pos. Pos, Pos,

c1335 c1336 @301 c1354F (RAA1151 @A1161 f A1142 RA1153 INVENTOR. THOMASF. CROCKER A TTORNEY Patented May 14, 1940 ST'iES ,acosta PATENT @FCETELEPHONE SYSTEM Application July 28, 1938, Serial No. 221,700

85 Claims.

The present invention relates to telephone systems and has for one ofits objects the provision of improved apparatus for rendering andsupervising toll services in such systems.

s In a telephone system adapted to handle toll traic, an exchange isprovided which includes a toll board comprising a number of groups ofoperators positions and at which the various groups of combined line andrecording or C. L. R. and toll lines terminate. Usually the toll boardcomprises a group of C. L. R. operators positions, a group of tolloperators positions and a group of point-to-point operators positions,these groups of operators positions being adapted to handle therespective types of toll services to be rendered. A local switch trainand a toll switch .train are provided in the exchange, each beingaccessible to each operators position at the toll board. In order tosupervise and coordinate the work of the operators at the variousoperators positions at the toll board and to advise the operators inregard to the services to be rendered, a plurality of auxiliaryoperators positions are associated with the toll board. These auxiliaryoperators positions usually comprise a chief operators position, a groupof supervisory operators positions, a group of rate and directoryoperators positions and a group of toll service observing operatorspositions. These auxiliary operators positions must also be coordinatedwith respect to each other in order to insure that prompt and eiiicienttoll services are rendered at the toll board. In order to accomplishthese ends, certain of the auxiliary operators positions have access toother of the auxiliary operators positions, to the local and toll switchtrains in the exchange and to the various C. L. R. and toll linesterminating at the toll board, in addition to access to each of theoperators positions at the toll board. Also, signal arrangements areprovided at the toll board and at the auxiliary operators positions inorder further to coordinate the work of the operators at the operatorspositions at the toll board and the operators at the auxiliary operatorspositions.

It is an object of the present invention to provide, in a telephonesystem or" the character noted including a toll board and a plurality ofauxiliary operators positions, improved apparatus for supervising andcoordinating the work of the operators at the operators positions at thetoll board in an eiiicient manner which comprises a minimum amount ofequipment.

Another object of the invention is to provide, in a telephone system ofthe character noted and including at least two auxiliary operatorspositions, an improved arrangement for selectively establishing amonitoring connection and a twoway communication connection between thetwo operators positions.

Another object of the invention is to provide, in a telephone system ofthe type described, a switch having access to a plurality of groups oflines, an operators position provided with apparatus successivelyoperative to perform successive control functions to cause the switch toselect a line in a particular group of lines, and an improvedarrangement for indicating to an operator at the operators position whenthe apparatus may be effectively operated to perform the successivecontrol functions.

It is another object of the invention to provide, in a telephone system,a switchboard comprising a plurality of operators switchboard positionsand an arrangement for assigning calls to the operators switchboardpositions in a predetermined order to be answered, another operatorsposition, and an improved arrangement for indicating to an operator atthe other operators position a predetermined time interval delay inanswering a call.

It is another object of the invention to provide, in a telephone system,a plurality of operators positions, a distributor for assigning calls tobe answered by particular idle ones of the operators positions in apredetermined order, and an arrangement controlled when all of theoperators positions are busy for assigning calls to be answered by anyone of the operators positions. 35

A further object of the invention is to provide, in a telephone system,a plurality of operators positions, and an improved distributor forassigning calls to the operators positions to be answered which ispreselective and fully directive in character.

It is a further object of the invention to provide, in a telephonesystem, a plurality of operators positions, an arrangement for assigningincoming calls to be answered to idle ones of the operators positions ina predetermined order, apparatus at each operators position operative toinitiate an outgoing call therefrom, and an arrangement controlled bythe operation of the apparatus at each operators position for preventingincoming calls from being assigned to Ythe operators position.

It is a further object oi the invention to provide, in a telephonesystem, a switchboard including a plurality of operators switchboard 55positions, an arrangement operative to select idle ones of the operatorsswitchboard positions in a predetermined order and to assign an incomingcall to a selected operators switchboard position, an arrangement forrouting a call from the operators switchboard position over an outgoingline, another operators position, and arrangements controlled by theselection of a particular operators switchboard position, by theassignment of a call on a particular incoming line thereto, and by therouting of the call over a particular outgoing line for transmittingcorresponding signals to the other operators position.

It is a further object of the invention to provide, in a telephonesystem, a switchboard including an operators switchboard positionadapted to route a call therethrough on a particular incoming line overa particular outgoing line, and another operators position provided withimproved apparatus for selectively monitoring a connection including theparticular operators switchboard position, a connection including theparticular incoming line and a connection including the particularoutgoing line.

The features of the present invention are illustrated as beingincorporated in a telephone system including an exchange provided with atoll board having groups of C. L. R. and toll lines terminating thereat,and a plurality of auxiliary operators positions associated with thetoll board and with each other in such a manner that the operators atthe operators positions at the toll board may be adequately advised andsupervised in order to insure that prompt and efficient toll servicesare rendered. The toll board includes a group of C` L. R. operatorspositions, a group of toll operators positions and a group ofpointto-point operators positions, a position distributor for assigningincoming C. L. R. calls to idle ones of the C. L. R. operators positionsin a predetermined order and a position distributor for assigningincoming toll calls to idle ones of the toll operators positions in apredetermined order. The auxiliary operators positions associated withthe toll board comprise a chief operators position, a group ofsupervisory operators positions, a group of rate and directory operatorspositions and a group of toll service observing operators positions.

In accordance with one feature of the invention, one of the supervisoryoperators positions is provided with a line extending thereto over whicha call is adapted to be routed. The chief operators position comprises atelephone instrument including a receiver and a transmitter, first andsecond repeaters being associated with the chief operators position,means for connecting the transmitter to the first repeater, means forselectively connecting the first and second repeaters to the lineextending to the supervisory operators position and automatic meanscontrolled by the last-mentioned means for connecting the receiver tothe first repeater when the rst repeater is connected to the line,thereby to cornplete a two-way communication connection between thechief operators position and the line, and for connecting the receiverto the second repeater when the second repeater is connected to theline, thereby toi complete a monitoring connection between the chiefoperators position and the line.

In accordance with another feature of the invention, the telephonesystem includes an exchange having a plurality of groups of linesassociated therewith and extending to dilerent distant exchanges and aswitch having access to the lines. Control apparatus is associated withthe switch and operative in response to a first control function toperform an intermediate operation which consumes an interval of time andoperative in response to at least one additional control functionsubsequent to the performance of the intermediate operation for causingthe switch to select a line in a particular one of the groups of lines.The chief operators position is provided with a signal and apparatus forperforming the control functions to which the control apparatus isresponsive. An arrangement is associated with the switch and the chief'operettors position for controlling the operation of the signal at thechief operators position during the interval of time the controlapparatus is performing the intermediate operation.

In accordance with another feature of the invention, a switchboard isprovided which comprises a plurality of operators switchboard positionsand has a plurality of lines associated therewith and extending to adistant exchange. A position distributor is associated with theswitchboard and is operative to assign a call on one of the lines to anidle one of the operators switchboard positions to be answered. A timerand a signal are associated with the chief operators position; and anarrangement is provided which is controlled by the presence of a call onone of the lines when all of the operators switchboard positions arebusy for causing operation of the timer, the timer being effective afterthe operation thereof for a predetermined time interval to causeoperation of the signal at the chief operators position.

In accordance with a further feature of thc invention, the telephonesystem includes a plurality of rate and directory operators positions.

a plurality of trunk lines individually extending l' to the operatorspositions, an auxiliary trunk line commonly associated with theoperators positions and to which each operators position has access, aswitch having access to the trunk lines and operative to seize one ofthe trunk lines, and a distributor associated with the rate anddirectory operators position for causing the switch to seize idle onesof the first-mentioned trunk lines in a predetermined order. Also anarrangement is provided which is controlled when all of the operatorspositions are busy for causing the switch to seize the auxiliary trunkline. In accordance with a further feature of the invention, thedistributor associated with the rate and directory operators positionsis operative to assign one of the first-mentioned trunk lines extendingto an idle one of the operators positions to be seized by the switchoperative in response to the seizure of the assigned trunk line by theswitch to assign another one of the iirst-mentioned trunk linesextending to an idle one of the operators positions to be seized by theswitch. In accordance with a further feature of the invention, a trunkline individually associated with each rate and directory operatorsposition extends to a second switch, and each operators position isprovided with means operative to seize the trunk line individuallyassociated therewith. Also. an arrangement is provided which iscontrolled when the trunk line individually associated with a particularoperators position is seized for rendering busy the one of the trunklines individually extending to the particular operators position.

In accordance with a further feature of the invention, the serviceobserving operators position is associated with the toll board, and anarrangement is provided which is controlled by the operation of thedistributor to select a particular operators switchboard position fortransmitting to the service observing operators position a signalcharacteristic to the particular operators switchboard position. Also anarrangement is provided which is controlled by the operation of thedistributor to assign a call on a particular one of the lines to theselected particular operators switchboard position for transmitting tothe service observing operators position a signal characteristic to theparticular line.

In accordance with a further feature of the invention, the linesassociated with the switchboard are divided into a group of incominglines and a group of outgoing lines, and a switch is provided which isoperative to route a call between a line in the inco-ming group and aline in the outgoing group, each operators switchboard position beingprovided with apparatus for controlling the operation of the switch. Asignal characteristic to a particular operators switchboard position istransmitted to the toll service observing operators position when theparticular operators position is selected by the distributor; a signalcharacteristic to a particular incoming line having a call thereon istransmitted to the toll service observing operators position when theparticular` incoming line is assigned to the particular operatorsswitchboard position; and a signal characteristic to a particularoutgoing line over which the call is to be routed is transmitted to thetoll service observing operators position after the switch seizes theparticular outgoing line. In accordance with a further feature of theinvention, equipment is provided at the service observing operatorsposition for selectively monitoring a connection including theparticular operators switchboard position, a connection including theparticular incoming line and a connection including the particularoutgoing line.

Further features of the invention pertain to the particular arrangementof the circuit elements whereby the above-outlined and additionaloperating features are attained. v

The novel features believed to be characteristic of the invention areset forth in the appended claims. The invention, both as to itsorganization and method of operation, together with further objects andadvantages thereof, will best be understood by reference to thefollowing specification taken in connection with the accompanyingdrawings in which Figure 1 illustrates the general arrangement of atelephone system embodying the present invention; Figs. 2 to l1,inclusive, illustrate the details of a system having incorporatedtherein the features of the invention as briefly outlined above; andFig. 12 illustrates the inode of combining Figs. 2 to 11, inclusive, ofthe drawings to form a unified system.

DEsoRIrTroN or THE APPARATUS INCORPORATED IN THE TELEPHONE SYsTEMReferring now more particularly to Fig. 1 of the drawings, the telephonesystem there illustrated comprises a local automatic exchange |25 andtwo distant automatic exchanges |05 and |06. The local exchange |25serves a number of local subscriber substations including the subscribersubstation indicated at C and associated with a subscriber line H3extending to the local exchange. Similarly, the distant exchanges |05and |06 each `serve a number of local subscriber substations includingthe subscriber substation indicated at A and associated with thesubscriber line extending to the distant exchange |05 and the subscribersubstation indicated at B associated with the subscriber line I 2extending to the distant exchange |05. The distant exchanges |05 and |06are respectively connected to the local exchange |25 by iirst and secondgroups of two-way toll lines respectively including the to-ll linesindicated at C'Hli and C'||5. Each end of each of the toll linesterminates in a toll line circuit individual thereto, the toll linecircuits terminating the ends of the toll lines C'Hll and C'HE at thelocal exchange |25 being indicated in the group of toll line circuitsH0.

The local exchange |25 includes a local switch train |01 having accessto each of the local subscriber lines and which preferably comprises aplurality of groups of selector and connector switches of the Strowgertype arranged in the usual manner. The local switch train |07 may becontrolled by an impulsing apparatus disposed at each subscribersubstation in order to set up the various connections between the localsubscriber lines in the usual manner. Similarly, the distant exchanges|05 and |05 are provided with local switch trains which may becontrolled by impulsing apparatus disposed at the local subscribersubstations in order to set up the various connections between the localsubscriber lines in the usual manner. Also the local exchange |25includes a toll switch train which preferably comprises a plurality ofgroups of selector and connector switches of the Strowger type arrangedin the usual manner, and which is utilized in a manner more fullydescribed subsequently in setting up the various toll connections.Similarly, the distant exchanges and |05 are provided with toll switchtrains which are utilized in setting up the various toll connections.

An automatic toll board |00 is arranged in the local exchange |25 andcomprises a group of C. L. R. operators positions, a group ofpoint-topoint operators positions and a group of toll operatorspositions, each operators position having access to both the local andthe toll switch trains |07 and |03, respectively. Associated with thetoll board |00 is a group of C. L. R. lines accessible to the localswitch train I0?, one of the C. L. R. lines being indicated at C'Ho andprovided with a C. L. R. line circuit |09. Position distributor and,common equipment |03 is associated with the C. L. R. linecircuits andthe C. L. R. operators positions in order to assign incoming C. L. R.calls tothe C. L. R. operators positions in a predetermined order.Position distributor and common equipment '|05 is associated with thetoll line circuits and the toll operators positions in order to assignincoming toll calls to the toll operators positions in a predeterminedorder. The toll switch train |05 has access to the local switch train|01 and to the toll line circuits in order to enable an operator at apoint-to-point operators position to render point-to-point service andto enable an operator at a to-ll operators position to render inwardland through service in a manner more fully described subsequently.

Associated with the toll board |00, the local switch train |01 and thetolll switch train |08 is a plurality of auxiliary operators positionsincluding a chief operators position, a number of lsupervisory operatorspositions, a number of 'rate and directory operators positions, and anurnber of toll service observing operators positions. In the systemillustrated, the chief operators position is indicated at one of thesupervisory operators positions is indicated at |02; one of the rate anddirectory operators positions is indicated at |03; and one of the tollservice observing operators positions is indicated at |04. The chiefoperators position |0| has access to and is accessible to the localswitch train |02 by way of a trunk line C1242, has access by way of thetrunk line C|241 to the toll switch train |08 and is accessible by Wayof a trunk line C|252 to the toll switch train|08. The chief operatorsposition |0| has access to the supervisory operators position |02 by wayof a trunk line C|330 and has access to the rate and directory operatorsposition |03 by way of a trunk line C|26.. Furthermore, the chiefoperators position |l| has access to each operators position at the tollboard |00 by way of a trunk line individual thereto, access being had tothe first toll operators position at the toll board by way of the trunkline C|258. Finally the position distributor and common equipment '|04is associated, by Way of the trunk line C|253, with the chief operatorsposition |0| for a purpose more fully described subsequently. Thesupervisory operators position |02 is accessible to the toll switchtrain |08 by way of the trunk line C|259. The rate and directoryoperators position |03 has access to the local switch train |01 by wayof a trunk line C|29|, is accessible to the toll switch train |08 by wayof a trunk line C|2| individual thereto and an auxiliary trunk lineC|2'|0 commonly associated with each rate and directory operatorsposition. The toll service observing operators position |04 isassociated with the position distributor and common equipment '|03 andwith the position distributor and common equipment '|04 by way of thetrunk line C|23| and C|232, respectively, for a purpose more fullydescribed subsequently. Also the toll service observing oper'atorsposition 04 is associated with a group busy apparatus '|05 by way of atrunk line C|222, while the group busy apparatus '|05 is associated Withthe toll line circuits ||0 of a particular group of toll lines by way ofa trunk line C12| for a purpose more fully described subsequently.Furtherniore, the toll service observing operators position |00 hasaccess to each operators position at the toll board |00 by way of atrunk line individual thereto, access to the rst C. L. R. operatorsposition at the toll boa-rd being had by way of the trunk line C|230,and access to the rst toll operators position at the toll board beinghad by way of the trunk line C|22|. Moreover, the toll service observingoperators position |04 has access to each C. L. R. and each toll linecircuit, access to one of the C. L. R. line circuits being had by way ofthe trunk line C 22B, and access to one of the toll line circuits beinghad by Way of the trunk line C|2|'|. Finally, the toll service observingoperators position |00 has access to each rate and! directory operatorsposition and access to each auxiliary trunk line associated with therate and directory operators positions, access being had to the rate anddirectory operators position |03 by way of the trunk line CIZ l0, andaccess being had to the auxiliary trunk lin@ C|2'l0 associated with therate and directory operators positions by Way of the trunk line C|308.

Preferably, the toll board |00, the position distributor and commonequipment 103 and the position distributor and common equipment 104,associated therewith, are of the construction and arrangement of thatdescribed and claimed in the copending application of Thomas F. Crocker,Serial No. 142,558, led May 14, 1937 now' Patent No. 2,167,710, issuedAug. l, 1939. Briefly, the toll board |00, as best shown in Fig. 7,comprises a rst group of operators positions which are utilized as tolloperators positions and a second group of operators positions which maybe utilized, either as C. L. R. operators positions or as point-to-pointoperators positions, each of the operators positions of the second groupbeing capable of being converted from one type of operators position tothe other merely by operating a key thereat. Accordingly the toll board|00 comprises a plural of toll operators positions, a plurality of C. L.R. operators positions and a plurality of point-to-point operatorspositions. In the system illustrated, the rst C. L. R. operatorsposition is indicatedy at |0| and the first toll operators position isindicated at "102. The position distributor and common equipment '10?.is so connected and arranged that it selects the C. L. R. operatorspositions in a predetermined order and assigns an incoming C. L. R. callto a selected C. L. R. operators position. Each C. L. R. operator-sposition is provided with a linklistening key which is operable to oneposition to cause the position distributor and common equipment 103 toselect the corresponding C. L R. operators position in the course ofoperation thereof and operable to another position after the positiondistributor and common equipment '|03 assigns an incoming C. L. R. callthereto. The position distributor and common equipment '|03 ispreselective and fully directive in that it selects an idle C. L. R.operators position having the link-listening key thereat occupying theone position, and subsequently assigns automatically a call on one ofthe C. L. R. lines thereto in response to the creation of a callingcondition on the one C. L. R. line. After the link-listening key at theone C. L. R. operators position is operated to the other position, theposition distributor and common equipment 103 operates automatically toselect another idle C. L. R. operators position having thelink-listening key thereat operated to the one position. Also, each C.L. R. operators position is provided with an answer key which isoperated t0 a predetermined position in order to answer a call on theone C. L. R. line assigned thereto and a ringing key which is Operatedt0 a predetermined position in order to cause ringing current to beprojected over an outgoing toll line over which a call is to be routed.Finally, each C. L. R. operators position is provided with a telephoneinstrument and an impulsing apparatus thereat in order to control theoperations of the local and the toll switch trains |0'| and |08,respectively.

Similarly, each toll operators position is provided with alink-listening key which is operable to one position to cause theposition distributor and common equipment '|00 to select thecorresponding toll operator-s position in the course of operationthereof, and operable to another posi.- tion after the positiondistributor and common equipment |04 assigns an incoming toll callthereto. The position distributor and common equipment '|04 ispreselective and fully directive in that it selects an idle tolloperators position having the link-listening key thereat occupying theone position, and subsequently assigns automatically a call on one ofthe toll lines thereto in response -on the one toll line assignedthereto and a ringing key which is operated to a predetermined positionin order to cause ringing current to be projected over an outgoing tollline, over which a call is to be routed. Finally, each toll operatorsposition is provided with a telephone instrument and an impulsingapparatus thereat in order to control the operations of the local andtoll switch trains |01 and |08, respectively. Group busy apparatus 105is associated with the toll line circuits of the group of toll linesextending to the distant exchange and is operable to transmit a signalto the toll service observing operator's position 00 when all of thelines in the group extending to the distant exchange |05 'are busy.

The chief operators position |0 l, as best shown in Figs. 3, 4 and theportion of Fig. 6 to the left of the dashed line, comprises a primarytelephone instrument including a transmitter 330 and a receiver 33|, asecondary telephone instrument including a transmitter 350 and areceiver 349, and an impulsing apparatus 325, the secondary telephoneinstrument being adapted to be connected by way of the plugs 334 and 338associated with the jacks 342 and 346, respectively, across therespectlve terminals of the primary telephone instrument. Associatedwith the primary telephone instrument are a iirst repeater 305 and asecond repeater 310. A trunk line C|230 and a monitoring plug 300 areprovided at the chief operators position I0| and an arrangementincluding a switch 300 is provided for controlling the association ofthe repeaters 305 and 310 with the trunk line Cl230 and the monitoringplug 300. A control relay R350 is provided for selectively connectingthe receiver 33| of the primary telephone instrument to the repeaters305 and 310. Two control relays R3|5 and R320 are associated with theiir'pulsing apparatus 325 for the purpose of completing a bridge patharound at least a portion of the repeater 305, and for interrupting theconnection of the receiver 33| to the repeater 305 when the impulsingapparatus 325 is operated, thereby respectively to establish a lowimpedance impulsing circuit between the impulsing apparatus 325 and thetrunk line Cl339, and to prevent clicks in the receiver 33|. The switch380 is provided with a normal position, a right-hand or ring positionand a left-hand or talk position. When the switch 330 occupies itsnormal position, the repeater 3l@ is connected to the monitoring plug300 and the repeater 305 is connected to the trunk line (2H-35; when theswitch 380 occupies its 'ring position, a source of ringing current isconnected to the monitoring plug 300 and the trunk line M239; and whenthe switch 380 occupies its talk position, the monitoring plug 300 isconnected to the repeater 305 and the trunk line (H239 is connected tothe repeater 305.

The chief operators position |0| has access to and is accessible to thelocal switch train |01 by way of the trunk line C |202 and a switch 400associated therewith. The switch 400 has a normal position, a right-handor talk position and a left-hand or hold position. When the switch 400is operated to its talk position, the trunk line C|239 is connected tothe trunk line Cl242, and when the switch 400 is operated to its holdposition a bridge is connected to the trunk line C|242, thereby toretain the local switch train |01 in operated position. A ring-up relayR460 is associated with the trunk line C|242 and is adapted toilluminate a lamp L402 at the chief operators position in order toindicate to an operator thereat a calling condition of the trunk lineCl242. Associated with the switch 000 and the ring-up relay R460 is aplurality of control relays R442, R645 and R050. These control relaysare so connected and arranged that an auxiliary bridge is connected tothe trunk line Cl2t2 when the switch 400 is operated from its talkposition or its hold position, thereby to prevent the release of thelocal switch train |01, these relays further interrupting the auxiliarybridge after a predetermined time interval in the event the switch 400is operated to its normal position, thereby to release the local switchtrain |01. Further, these control relays control the disconnection ofthe ring-up relay R400 from the trunk line C|242 and, consequently, theillumination of the lamp L, Finally, these control relays control acharging circuit for the lring-up relay R460 which is provided for thepurpose of preventing false operation of the ring-up relay R450 by theswitching surges ci current projected over the trunk.l line C|242incident to the release oi the local switch train |01.

The `chief operators position |0| has access to the toll switch train|08 by way of the trunk line Ci241 and a switch 421 associatedtherewith. The switch 021 has a normal position, a righthand or talkposition and a left-hand orv hold position. When the switch 421 isoperated to its talk position, the trunk line C1239 is connected to thetrunk line Cl 241 and, when the switch 421 is operated to its holdposition, two control relays R414 and R015 are operated. The controlrelay R415 controls the release of the toll switch train |08 and theoperation of `a signal at the toll board |00. Also, an arrangementincluding a control relay R358 and a lamp L300 is provided for thepurpose or indicating to an operator at the chief operators position I0|the time interval during which a selector switch in the toll switchtrain is hunting for a trunk line extending to a connector switch havingaccess to the desired toll line.

The chief operators position |0| is accessible to the toll switch train|00 by way of the trunk; line C|252 and a' switch M3 associatedtherewith. The switch H3 has a normal position, a righthand or talkposition and a left-hand or hold position. When the switch H3 occupiesits talk position, the trunk line C1230 is connected to the trunk lineC9252, and when the switch H3 occupies its hold position the operationor a control relay R400 is controlled in order to retain the toll switchtrain |03 in operated position. A control relay R412 is associated withthe trunk line C|252 for the purpose of operating a signal lamp- L401when a calling condition is created on the trunk line Cl252. Also, acontrol relay R468 is provided for the purpose of extinguishing the lampL461, the operation of the last-mentioned control relay being under thejoint control of the control relays R464 and R012.

The chief operators position |0| also embodies signaling apparatus 080associated with the toll board |00. More particularly, the signalingapparatus 480 is associated with the position distributor and commonequipment 100 at the toll board and is so connected and arranged that anindication is given to an operator at the chief operators position whena toll call in the inward group of toll trunks at the toll board has apredetermined delayed answering time. More specifically. the signalingapparatus 53|) comprises a lamp LMS, a plurality of control relaysRlltli, R482, Rllll, R488 and R496 and a trunk line Clt associated withapparatus in the position distributor and common equipment- "ru Thearrangement is such that operations of these control relays areinitiated in the event that all of the toll operators positions are busyand there is no toll operatorsI position to which an incoming toll callmay be assigned by the position distributor and common equipment 781i.These control relays constitute a timer and, after operating apredetermined time interval, cause the lamp Lt to be illuminatedintermittently.

The monitoring` plug 300 is associated with rst, second and third groupsof jacks, the rst group of jacks being connected to trunk linesextending to the respective supervisory operators positions, the secondgroup of jacks being connected to trunk lines extending to therespective operators positions at the toll board |00 and the third groupof jacks being connected to trunk lines extending to the respective rateand directory operators positions. In the arrangement illustrated, thejack E05 included in the first group is connected by way of a trunk lineCllil to the supervisory operators position |013.; the jacl; 5|@included in the second group is ccnnected to a. trunk line C|258extending to the rst toll operators position '|02 at the toll board HBO;and the jack @l5 is connected to a trunk line Cll extending to the rstrate and directory operators position |03. When the monitoring plug 300is inserted into the jack E505, a monitoring connection is automaticallyestablished from the chief operators position |05 to the supervisoryoperators position E02, and this connection may be automaticallyconverted into a two-way communication connection therebetween byoperating the switch 380 to its talk position. When the monitoring plug300 is' inserted into the jack Gl, a monitoring connection isautomatically established from the chief operators position l QI to therst toll operators position if?? at the toll board |00, and thisconnection may be automatically converted into a two-way communica--tion connection therebetween by operating the switch 3&0 to its talkposition. When the monitoring plug 300 isI inserted into the jack Gi, amonitoring connection is automatically established from the chiefoperators position l0! to the iirst rate and directory operatorsposition |05, and this connection may be automatically converted into atwo-way communication connection therebetween by operating the switch380 to its talk position.

The jack Gli) has a lamp M529 individually associated therewith which iscontrolled jointly by the busy or idle condition of the rst tolloperators position '|02 at the toll board and a master switch 620 at thechief operators position |0|, the master switch 52! being connected andarranged in the circuits for illuminating the lamp 1.629 and the otherlamps individually associated with the other jacks corresponding to thejack 6|0 and extending to the other operators positions at the tollboard.

Two lamps L63!! and LGSS are individually associated with the jack SI5,the lamp T4534 being connected and arranged to be illuminated when therst rate and directory operators position |03 answers a call on the rstauxiliary trunk line CZl'li, and the lamp being connected and arrangedto be illuminated when the rst rate and directory operators position |03is rendered busy by operating a switch |060 thereat. The supervisoryoperators position I 02, as best shown in Fig. 6 to the right of thedashed line, comprises' a telephone instrument including a transmitter'll and a receiver 679, a repeater 600, a signal lamp L5M, an alarm8530, and an arrangement comprising two plugs 058 and G62 and two jacksGGG and 610 for connecting the telephone instrument to the repeater 690.The supervisory operators position |02 is accessible by way of the trunkline C|339 to the chief operators position Hl! and accessible by way ofthe trunk line C|26l to the toll switch train |08. The supervisoryoperators position |02 also includes a plurality of control relaysRG/itl, R644, R552 and Ri and a ring-up relay R650 for con-- trollingthe illumination of the lamp L649, for controlling the operation of thealarm 680 and for controlling the marking of the trunk line CIZGQ asbusy to the toll switch train |08.

Associated with the rate and directory operators positions, as bestshown in Figs. 9 to l1, inclusive, is a position distributor H70 whichcomprises a plurality of control relays RIHU, REUS, Rll'i, RI 00. Thisposition distributor |70 is connected afmA arranged to assign three rateand directory operators positions in a predetermined order to the use ofthe operators at the toll board I. position it comprises a telephoneinstrument including a transmitter |0|3 and a receiver |0| 4, animpulsing apparatus lBl, a repeater 9H! and a plurality of controlswitches |020, |030, |040 and |050. The iirst rate and directoryoperators position Yl0?. is accessible by way of the trunk line C|27|individual thereto to the toll switch train |08 and accessible by way ofthe trunk line CIZ'LL commonly associated with each rate and directoryoperators position to the toll switch train m8. An arrangement includingtwo plugs will and ltl and two jacks |00| and |904 is provided forconnecting the telephone instrument at rate and directory operatorsposition |53 to the repeater SID. The switch |040 is operable betweentwo positions to selectively connect the rate and directory operatorsposition l 53 to the trunk line C|2`|| and the auxiliary trunk lineCl2'i0. A plurality of control relays Ptsif'l, R940 and R935 areassociated with the rate and directory operators position |03, and soconnected and arranged that a zip-zip tone is produced in the receiver|0|4 when the toll switch train $013 seizes the trunk line C|2`||assigned to be seized by the distributor H70. Also, a control relay R isassociated with the rate and directory operators position E03 in orderto control the marking of this position as busy to the toll switch trainMES under the control of the telephone instrument thercat. The switch|060 has a normal position, right-hand and left-hand positions. When theswitch |060 occupies a right-hand position a signal is operated at thetoll board |00, and when the switch |060 occupies a left-hand positionthe rate and directory operators position |03 is rendered busy to thetoll switch train |00 and a signal is operated at the chief operatorsposition |0|. Further a control relay R950 is associated with the rateand directory operators position |03 which is connected The iirst rateand directory operators 3 Ail) and arranged to control a signal at thechiel operators position |9| to control the operations of the lampsL|939 and L|931 at the rate and directory operators position |93, and tocontrol the marking of the trunk line Ci|21| as busy to the toll switchtrain |98 when the rate and directory operators position |93 isconnected to the auxiliary trunk line C|219.

Associated with the auxiliary trunk line C|219 are a plurality ofcontrol relays R969, R965, R915,

-R985 and R995, the control relays R995, R915 and R985 also beingrespectively associated with the first, second'and third rate anddirectory operators positions. The control relay R995 is connected andarranged to control the operation of the control relay R969, whichlatter relay controls the operations of the signals at each rate anddirectory operators position when the toll switch train |98 seizes theauxiliary trunk line C |219. The control relay R965 is connected andarranged to be controlled at the first rate and directory operatorsposition |93 and is effective to control the operation of the controlrelay R959. in a similar manner, the control relays R915 and R985 areconnected and arranged to be controlled at the second and third rate anddirectory operators positions, respectively.

The first rate and directory operators position |93 has access b-y wayof a trunk line C|29| individual thereto to the local switch train |91,and the impulsing apparatus |9| 5 and the repeater 9 I9 thereat areconnected to the trunk line Cl29| when the switch |929 is operated fromits right-hand position to its left-hand position. Also an arrangementincluding the switch |939 is provided for holding the local switch train|01 in operated position independently of the impulsing apparatus |9|5and the repeater 9|9.

The service observing operators position |94, as best shown in Figs. 2,5 and 8, comprises a receiver set 851 including two receivers 858 and859 individually associated with two plugs 894 and 891, respectively,and two signal current amplifiers 859 and 869 which are respectivelyassociated with two pairs of jacks 819, 882, and 816, 898. The amplifier859 is associated with a switch 829 connected to a monitoring plug 89|and the amplifier 859 is associated with the switch 839 having a normalposition and right-hand and left-hand positions. When the switch 839occupies a right-hand position, the amplifier 869 is connected to amonitoring plug 895, and when the switch 839 occupies a left-handposition the amplifier 859 is connected to a monitoring plug 8|9. Thetoll service observing operators position |94 is also provided with aplurality of jacks individually associated with the toll line circuits,a plurality of jacks individually associated with the toll operatorspositions, a plurality of jacks individually associated with the C. L.R. line circuits, a plurality of jacks individually associated with theC. L. R. operators positions, a plurality of jacks individuallyassociated with the rate and directory op-erators positions, and aplurality of jacks individually associated with the auxiliary trunklines commonly associated with the rate and directory operatorspositions. In the arrangement illustrated, the jack 519 is individuallyassociated with one ofthe toll line circuits |9; the jack 515 isindividually associated with the first toll operators position 192; thejack 589 is individually associated with one of the C. L. R. linecircuits |99; the jack 585 is individually associated with the iirst C.L. R. operators position 19|; the jack 599 is individually associatedwith the iirst rate and directory operators position |93; 4and the jack525 is individually associated with the first auxiliary trunk line C|219commonly associated with the rate and directory operators positions. Agroup of control relays is individually associated with the jacksassociated with the toll line circuits, and a group of control relays isindividually associated with the jacks associated with the C. L. R. linecircuits. In the arrangement illustrated, a control relay R555 isassociated with the jack 519 and a control relay R565 is associated withthe jack 589. Further, a control relay R569 is associated with theposition distributor 193 and a control relay R559 is associated with theposition distributor 194. A number of lamps L551, 1,558, L551 and L558are respectively associated with the control relays R555, R559, R555 andR559. The operation of the control relays R559 and R599 are under thecontrol of the position distributors 194 and 193, respectively, and theoperation of the control relays R555 and R565 are under the control ofone of the toll line circuits |I9 and one of the C. L. R. line circuits|99, respectively. Also, two control relays R529 and R539 arel providedin order to control the operation of the control relays R559 and R555and two control relays R5|9 and R549 are provided in order to controlthe operation of the control relays R569 and R555. A control relay R239is provided which is controlled by the operation of the switch 839, andtwo control relays R249 and R259 are provided which are controlled bythe operation of the ringing keys at the operators positions at the tollboard |99. Two control relays R599 and R595 are provided in order tocontrol the operation of a control relay corresponding to the controlrelay R555. Further the control relays R249 and R259 control theillumination of a supervisory disconnect lamp L29! and a supervisoryringing lamp L292 at the toll service observing operators position |94.The operation of the various control relays are controlled by aplurality of switches 295, 2|9, 2|5, 229 and 225 at the toll serviceobserving operators position |94. By utilizing the equipment at the tollservice observing operators position |94, in a manner more fullydescribed subsequently, all of the services rendered by the operators atthe various operators positions at the toll board |99 may be monitored.Furthermore, the arrangement of the control relays and the lamps at thetoll service observing operators position |94 is such that an operatorat the toll service observing operators position |94 is adequatelyadvised as to which operators position at the toll board the service isto be performed at and which C. L. R. and toll lines are involved in thevarious connections.

Operation of the apparatus at the toll board The toll board |99comprises a plurality of combined line and recording or C. L. R.operators positions and a position distributor 193 associated therewithfor the' purpose of selecting the positions and assigning incoming C. L.R. calls thereto as previously noted. More particularly, the positiondistributor |93 selects sequentially the C. L. R. operators positionshaving operated link-listening keys and assigns an incoming C. L. R.call to the selected C. L. R operators position When the positiondistributor 193 operates to select a particular C. L. R. operatorsposition, it applies ground potential to the control conductorindividual to the position and extending to the toll service observingoperators position ii. For example, when the position distributor w3operates to select the rst C. L. R. operators position it, groundpotential in the position distributor 'i513 is applied to the controlconductor (H235 individual to this position and extending to the tollservice observing operators position E04. This application of groundpotential to the control conductor CIZSI causes the position lamp L568at the toll service observing operators position E64 and individual tothe lrst C. L. R. operators position 10| to be illuminated under certainoperating conditions, in order to assist the operator at this positionin observing the service rendered by the operator at the rst C. L. R.operators position 10|, in a manner more Jfully explained subsequently.When the operator at the rst C. L. R. operators position itil answers anincoming C. L. R. call assigned thereto by the position distributor Vit,the link-listening key thereat is returned to its busy position and theposition distributor T53 operates automatically to select another C. L.R. operators position to receive the next incoming C. L. R. call. Theposition distributor SSS also operates at this time to remove groundpotential from the control conductor 0323i, thereby to perform, underthe operating conditions noted, a function at the service observingoperators position Hifi, as is more fully explained subsequently.

The operator at the iirst C. L. R. operators position "mi may seize thetoll switch train 08 and dial a series of digits thereinto to cause t toseize an idle toll line in a particular group of toll lines. When thetoll switch train its is operated to seize an outgoing toll line, groundpotential in the toll switch train is applied to the control conductorof the trunk line. For exampie, when the toll switch train 38 seizes theoutgoing toll line C'Hli, ground potential in the toll switch train isapplied to the control conductor thereof, which ground potential isconducted by way of the toll line circuit individual to the toll line C7l@ to the control conductor CH2 l 6 of the trunk line C2il extending tothe service observing operators position idd, thereby to cause, underthe operating conditions noted, the toll line lamp 1355's' individual tothe toll line C'I I4 to be illuminated.

After an outgoing toll line has been seized by the toll switch train lS8, the operator at the rst C. L. R. operators position operates theringing key at this position, thereby to cause ringing current to beprojected over the outgoing toll line and to cause ground potential atthis position to be applied to the control conductor Cl229 of the trunkline CIZ individually associated with the first C. L. R. operatorsposition. This application of ground potential to the control conductorC5228 of the trunk line Ci23i! causes, under the operating conditionsnoted, the ringing supervisory lamp L29? at the toll service observingoperators position Hifi to be illuminated. When the toll operator in thedistant exchange answers the toll call extending thereto, the operatorat the rst C. L. R. operators position '16! operates the ringing key ather position to arrest the application of ringing current to theoutgoing toll line extending to the distant exchange. When this ringingkey is thus operated, ground potential is removed from the controlconductor C|229l of the trunk line CIZSS, thereby to cause, under theoperating conditions noted, the ringing supervisory lamp L?i to beextinguished. In

order to release the established connection extending to the distantexchange, the operator at the rst C. L. R. operators position 78operates a release key at her position, causing ground potential to beapplied through a resistor to the control conductor Ci229 of the trunkline CiZIiS, thereby to cause, under the operating conditions noted, thedisconnect supervisory lamp L20! at the toll service observing operatorsposition 904 to be illuminated.

The toll board also comprises a plurality oi toll operators positionsand a position distributor 'ili associated therewith for the purpose oiselecting the positions and assigning incoming toll calls thereto. Moreparticularly, the position distributor 'H14 selects sequentially thetoil operators positions having operated link-listening keys and assignsan incoming toll call to the selected toll operators position. When theposition distributor i055 operates to select a particular toll operatorsposition, it applies ground potential to the control conductorindividual to the position and extending to the toll service observingoperators position |04. For example, when the position distributor 'floperates to select the first toll operators position 792, groundpotential in the position distributor 'iS/i is applied to the controlconductor C|232 individual to this position and extending to the tollservice observing operators position Ili. This application of groundpotential to the control conductor CITY-32 causes the position lamp1.558 at the toll service observing operators position teli andindividual to the first toll operators position '102 to be illuminated,under certain operating conditions, in order to assist the operator atthis position in observing the service rendered by the operator at thefirst toll operators position 7&2, in a Inanner more fully explainedsubsequently. When the operator at the rst toll operators position TD2answers an incoming toll call assigned thereto by the positiondistributor 7M, the link-listening key thereat is returned to its busyposition and the position distributor 184 operates automatically toselect another toll operators position to receive the next incoming tollcall. The position distributo-r li also operates at this time to removeground potential from the control conductor CIZSZ, thereby to perform,under the operating conditions noted, a function at the serviceobserving operators position i343, as is more fully explainedsubsequently.

The operator at the first toll operators position E92 may seize the tollswitch train ltt and dial a series of digits thereinto to cause the tollswitch to seize an idle toll line in a particular group of toll lines,thereby to cause, under the operating conditions noted, the toll linelamp individual thereto at the toll service observing operators position84 to be illuminated as previously explained.

After an outgoing toll line has been seized by the toll switch trainID3, the operator at the iirst toll operators position operates theringing key at this position, thereby to cause ringing current to beprojected over the outgoing toll line and to cause ground potential atthis position to be applied to the control conductor C5229 oi' the trunkline CHEZ! individually associated with the iirst toll operatorsposition. This application of ground potential to the control conductorC5228 of the trunk line C|22I causes, under the operating conditionsnoted, the ringing supervisory lamp L2 G2 at the toll service observingoperators position |04 to be illuminated. When the toll operator in thedistant exchange answers the toll call extending thereto, the operatorat the first toll operators position 102 operates the ringing key at herposition to arrest the application of ringing current to the outgoingtoll line extending to the distant exchange. When this ringing key isthus operated, ground potential is removed from the control conductorCI22 of the trunk line CIZ? I, thereby to cause, under the operatingconditions noted, the ringing supervisory lamp L2Il2 to be extinguished.In order to release the established connection extending to the distantexchange, the operator at the rst toll operators position 102 operates arelease key at her position, causing ground potential to be appliedthrough a resistor to the control conductor C1220 of the trunk lineCI22I, thereby to cause, under the operating conditions noted, thedisconnect supervisory lamp L20I at the toll service observing operatorsposition H54 to be illuminated.

An arrangement is provided at the toll board Illll in order to indicateto the toll service observing operators position IEM when all of thetoll lines in a particular group at the toll board are busy. Forexample, an arrangement is provided for indicating when all of theoutgoing toll lines extending to the distant exchange M15 are busy,which comprises a group busy apparatus 105 individually associated byway of the trunk line C12I with the line circuits of the group ofoutgoing trunk lines extending to the distant exchange H35, a controlconductor CIEM and a lamp L519 located at the toll service observingoperators position IM. When all of the outgoing toll lines extendingfrom the toll board lili! to the distant exchange |05 are busy, thegroup busy apparatus 105 individually associated therewith by way of thetrunk line 012| is operated, to apply ground potential to the controlconductor CI222, thereby to cause the lamp L519 to be illuminated.

The position distributor 1&4 is so connected and arranged that groundpotential is applied therein to the control conductor CI253 extending tothe chief operators -position lill when the position distributor may notoperate to assign an incoming toll call to one of the toll operatorspositions due to the fact that none of the linklistening keys at thetoll operators positions are operated to cause the position distributortooperate to select the corresponding toll operators position. Theapplication of ground potential to the control conductor CI2525 causesthe lamp L498 at the chief operators position IBI to flash after a timeinterval of approximately four seconds, thereby to indicate to theoperator at the chief operators position that an incoming toll call hashad a delayed answering time of approximately four seconds.

Each of theC. L. R. operators positions and each of the toll operatorspositions has access to the toll switch train |08. More specically, thefirst C. L. R. operators position 10| has access to the toll switchtrain lll by way of a group of trunk lines including the trunk linesC1i8 and Cll, and the iirst toll operators position 102 has access tothe toll switch train by way of a group of trunk lines including thetrunk line C120. Also, the toll switch train I is accessible to thechief operators position i0! by way of the trunk line C3241. The tollswitch train il has access byway of the trunk line CI252 to the chiefoperators position IUI, access by way of the trunk line CIZBS to thesupervisory operators position I 32, access by way of the trunk line C l21I to the rate and directory operators position H13, and access by wayof the first auxiliary trunk line Ci21 to each of the rate and directoryoperators positions. The toll switch train m8 also has access by way ofa group of trunk lines including the trunk line C119 to the local switchtrain 01, and access by way of the trunk lines C111 and C123 to the tollline circuits individual to the toll lines C1il and Cll, respectively,included in groups of toll lines extending to the distant exchanges H35and it, respectively. The local switch train w1 is accessible by way ofthe trunk line CI2l2 to the chief operators position I@ I, andaccessible by way of the trunk line Ci 251i to the rate and directoryoperators position HB3. Also, the local switch train is accessible tothe subscribers station C by way of the subscriber line 1I3. The localswitch train |01 has access by way of the subscriber line 'I i3 to thesubscribers substation C, and access by way of the trunk line CIEM! tothe chief operators position I Si. Further, the local switch train m1has access by way of a group of C. L. R. lines including the C. L. R.line C1Ili, the line circuits individual thereto, and the trunk lineC122 to the position distributor 183. Each incoming toll line, includingthe toll lines CTM and C1l5, has access by way of the toll line circuitsindividual thereto and the trunk line C123 to the position distributor104.

In order to extend a call initiated at the substation A associated withthe distant exchange 05 to the substation B associated with the distantexchange It and routed by way of the toll board la, the subscriber atthe substation A removes the receiver of the telephone instrumentthereat from its hook and dials a proper series of digits into the localswitch train in the distant exchange IIlE in order to establish aconnection to a C. L. R. operators position thereat. The operator at theC. L. R. operators position in the distant exchange H35 answers the calland, after receiving the information concerning the called substation B,dials a proper series of digits into the toll switch train therein inorder to cause the toll switch train to seize an idle toll line, such,for example, as the toll line C1l 4 extending to the toll board Ill. Theincoming toll call on the toll line C144 is routed by way of the tollline circuit individual thereto, the trunk line 123', and the positiondistributor 194 to one of the toll operators positions. Assuming thatthe call is routed to the rst toll operators position 182, the operatorat this position answers the call and receives the informationconcerning the called substation B. The operator at the toll operatorsposition 1&2 then seizes the toll switch train IBS by way of the trunkline C and dials a proper series of digits thereinto to cause the tollswitch train to seize the trunk line C123 extending by way of the tollline circuit individual to the toll line C1l5 to the toll linev C'II5.The operator at the first toll operators position 152 then operates theringing key thereat to project ringing current over the outgoing tollline C1I5, causing the toll call to be answered at the distant exchangeIS by a toll operator thereat. The toll operator in the distant exchangeH16 then receives the information concerning the called substation B anddials a proper series of digits into the switch train therein to causethe subscriber line 112 to be seized. Ringing current is then projectedover the subscriber line 1I2 extending to the substation B. When thesubscriber at the substation B answers the call, the toll operator inthe distant

